The invention relates to a device for fixing a movable window pane on a window regulator of a motor vehicle and is suitable for so-called blind assembly.
From DE 31 08 244 A1 a coupling device is known between a pane lifter and a window pane of a motor vehicle which basically comprises a holding element fixed on the lower edge of the window pane and at least one coupling jaw which is equipped with detent means and projects in the direction of a coupling element which is provided with complementary detent elements and is connected to the window regulator mechanism. When bringing together the parts which are to be connected there is an elastic deformation of at least one of the coupling elements until the clip-fit connection is produced by positive interengagement of the detent means.
There is the drawback however that in order to produce the connection between the window pane and window regulator the spreading area must have a minimum elasticity so that the detent elements can enter into positive engagement.
This elasticity also creates the danger that with severe stresses, as may occur for example when a window pane is frozen on the frame, the detent elements may come out of engagement again. The window regulator device could then no longer fulfill its function. Furthermore it is difficult to bring the detent elements precisely into position relative to each other where they stand opposite one another so as to snap fit with each other. It is therefore often necessary to slide the window pane to and fro in the X or vehicle longitudinal axis direction in order to achieve a positive lock.
From JP 6-135228A a device is known for connecting a window pane to a window regulator which uses U-shaped profiled members on the window regulator extending parallel to the lower edge of the pane wherein the free arms of the U profile have inwardly directed hook-like projections. These profiled members are associated with complementary coupling members which can engage in the U-shaped hollow cavity and which are fixed on the lower edge of the window pane. In order to facilitate engagement the free ends of the coupling members are formed wedge-shaped with the barb-like projections being able to engage behind the projections of the U profile. Nevertheless it is generally necessary for the worker to exert pressure on the window pane in the assembly direction in order to produce the necessary keyed engagement. The position between the window regulator and window pane is fixed by means of screws corresponding to the holes and grooves provided. An adjustment of the window pane in the X-direction (vehicle longitudinal axis) for the purpose of setting an ideal position is no more possible than with the embodiment first described.
A fixing device with a substantially U-shaped base member is known from DE 44 26 670-A1. A variation of the embodiment for blind assembly uses a spring clasp engaging round the base member and having an elbow lever mounted thereon for articulated movement as the tension element. The free end of the elbow lever engages in the non-tensioned state through a recess of one of the arms into the gap of the U-shaped base member. On inserting the window pane into the gap between the clamping jaws (arms) the lower edge of the pane enters into engagement with the free end of the elbow lever and is swivelled with further insertion of the window pane over the dead point of the tension system in order then to snap automatically into the stable tension state. The spring clasp which is now tensioned presses the arms of the U-shaped base member against the surface of the window pane in order to fix this with clamping action (i.e. with friction engagement).
The drawback here, however, is that the clamping forces which can be produced with the solution described are not sufficient in each case to withstand the withdrawal forces which actually occur. On the other hand the maximum clamping forces permanently exist which produces high permanent strain on all the parts lying in the force flow. Furthermore the production of the clamping force required over the lower edge of the pane is not without problems since high mechanical strains can lead to breakage of the pretensioned vehicle panes.